The present invention relates to the automatic control of passenger vehicles, such as mass transit vehicles or the like, and including the decoding of wayside provided speed codes for vehicles speed control and speed maintenance purposes while the vehicle is moving along a track.
In an article entitled The BARTD Train Control System published in Railway Signaling and Communications for December 1967 at pages 18 to 23, the train control system for the San Francisco Bay Area Rapid Transit District is described. Other articles relating to the same train control system were published in the IEEE Transactions On Communication Technology for June 1968 at pages 369 to 374, in Railway Signaling and Communications for July 1969 at pages 27 to 38, in the Westinghouse Engineer for March 1970 at pages 51 to 54, in the Westinghouse Engineer for July 1972 at pages 98 to 103, and in the Westinghouse Engineer for September 1972 at pages 145 to 151. A general description of the train control system to be provided for the East-West line of the Sao Paulo Brazil Metro is provided in an article published in IAS 1977 Annual of the IEEE Industry Applications Society at pages 1105 to 1109.
It was known in the prior art to provide a checked redundancy speed error determination as disclosed in U.S. Pat. No. 3,749,994 of T. C. Matty. It was also known in the prior art to provide coded ones and zero speed signals, with the message information frequency coded and the timing information phase coded as disclosed in U.S. Pat. No. 3,810,161 of A. P. Sahasrabudhe. It was known to provide a speed command signal decoding apparatus as disclosed in U.S. Pat. No. 3,992,698 of A. P. Sahasrabudhe et al. It was also known in the prior art to individually decode the ones data and the zeros data, and then compare them to detect any discrepancy as disclosed in U.S. Pat. No. 4,015,082 of T. C. Matty et al.
A general description of the microprocessors and the related peripheral devices as shown in FIGS. 1 and 2 of the drawings is provided in the Intel 8080 Microcomputer System Users Manual currently available from Intel Corp., Santa Clara, California 95051.